SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6454d478100e0e0a1f60117fc15358f02ec6cd112ef0bf03af26793f377a303e' 
  AND token = 'gtSUcGoUWdmxWmuFbyjliUQPfhlw87GlHZTsB+tC0wQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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