SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd09f1e3cc317ee559371a4977e1ec92d24a304fc6b507f671feabc8fbbd68bb2' 
  AND token = 'E0459+9taWNFBc6VYNwaxrdLF4Qws3cnmydjcrBDF+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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