SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '400db4884f3eff26929297ec6bf6d29b296b3d7f2eff65a5841fae85d37a7575' 
  AND token = 'RF9DOxdbJMZdiqQP5GHnXSVDQKlLLSAkI8fDRIgMimg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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