SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd030e8d11d0ca4ba5909576d07b417de941f3a077c0c903c24c8857fe425877d' 
  AND token = 'pQCcXMz/OnWBsJzoB6M1MSK77vBUeR+fYWMuzy5bHj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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