SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b7cebc690101b41fe24acb6cc0f972f6612c0f006b0b510138505fbee4fff0c' 
  AND token = 'Q7ggdNgAEMWsckWCnB7EBNcvR8ArFvX5v3UmqJJ3Foc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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