SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e91d8c8852d5a25cb2ffda9bb76f9b6f9d923da9ba79ba760b6131becc1c6eb1' 
  AND token = 'wQqizZjZo3CGSlfJuMgztK1SXhi4dFxZLgRNaGqJJdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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