SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddcf67542cbc193d4987bfeddabc4300fd55edd5d5f69a577738b435d613d7c5' 
  AND token = 'i50Cs3URE6BzoGLLRhsV48M9TYlYDsXvJuDH4hqrbYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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