SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c176b2847fae411c48727e2a4c062fa9afcbbc0d3a39cb12f0fe2527cfcfcb05' 
  AND token = '1W1QMtPvcKYOMTMJAJwukVv0E7a0yE/vrk4pGYrbaPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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