SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0993d28dd80d4d55ef7f8b21a313ce5581daff7a246cfa84316cf68f1c03eb5' 
  AND token = 'LROPn1yG7D7Bb8l9R6kWRhsEM/f3H9dZ2M0jMT6bDo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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