SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de98e647f72831704d7648fc2186dbe78cb7b85bb9c96ab3e48fc88a52efc1a4' 
  AND token = '4G3CM7mlBLTj1WsWRorF/sYEHFzjJnz+2RGew/N8Dw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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