SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c478abc1cabd487bf992ba602c9461ecd4cdd1229f0760357324b8b10affbd0e' 
  AND token = 'Vqc5Ht7u1skWHdtDCk04H3QYtHCsI9Q9alwlhWp9zJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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