SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e18a707b0a3eeda44bd2e10d304c71e76bc686cbb3eceb1c1a121024178d591' 
  AND token = 'PFdvWXf2yyNkDA4nb32es6M9LkAy32tVmb+nfP7JDKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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