SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd44799f490858fa76a47c650858fb555c452d34ce846ae17de3883cecb5ed83' 
  AND token = 'vz5l5KuoFjpvvcvR4+iVCZmnh9I6mLpiPHzEeqVNmdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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