SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5cfbe79da43ed429abafc6f2814766fabbb976aa3518f5cbe7b08c025db2d79' 
  AND token = 'CsuHeesUjPWPw7ezilCizCo1RB5RrHYdyeFBQy/GFYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}