SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff707c9798e17ac0f229eab3a2f3a98f5e30fefeac330090142bc973d09493c7' 
  AND token = 'RUdNgAH2jU6XasDBp5p4+A9hMx1/+1Z8MCLETKJf3NU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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