SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '259a8942b8197cb9c0701f2333f384ce0edbf4d89dbd943bf349ead0568ffdf7' 
  AND token = 'DwvXEBszIZOnKORGimRq203FehMmjPacXXdqR8YWSvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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