SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80536d5e0a2a4c8ecfbe32d36117320c54b09138e525260fead7499316b803cd' 
  AND token = 'jZ/zheB1Tj2JGZumqPgGyIao/2Wdds71ks551SdWaw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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