SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af83385b4239b2e3352c28f13f772713707a68379c7677b58c62ac72b3a221c5' 
  AND token = 'TkR0G/kPmiyusLZVk0FGncMnOjMpgdjfe2oyvK2ulUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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