SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fb80720d1c6a86b6a25b5335bf9c983af80489802ae051f5348aae1b14189b2' 
  AND token = 'm6pAn7YKzBxj3a+0AuQ13iJp7EkBQbfY33MmB0NbJeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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