SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c85738d926c8b1082620baba7cdceace6ef5286473d48923fcb41289fe0ba6ee' 
  AND token = 'GMVTWQypqMtTgqEn91okVl+DDZSc99YRIp+5s2civf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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