SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52175f2abc4f4dae79ef06769be34c2091534bfc51416092de0098fa227bf75a' 
  AND token = '8K2hR3LzvDUYR3IJ+lKIls3ouP4mk88ZdV/2wyQ7BfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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