SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a1ff4ebc6b87824b26dac2f7c9df9f53b8ea20a7893113ab06d9503982a9ca4' 
  AND token = 'B+5bQx+RJoYMyKasw4/OhvUov5N+snNQBY82SnrWC3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}