SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4150761fe277d15a1af721e57e6996c6c897c6517aea628407c3b611373a5971' 
  AND token = 'h7Ptdzm64SjsMGtgM11KMOqLqjODmMGUw9IDUgXEBd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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