SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9458e2b7b4f84a33cbe93dce9cc48b4fd9b4b2a97731e5d3a9cefb8bb7108c62' 
  AND token = 'iEBwUcnobFAWv802Bd3h3eUX1KGW89GtycAvG9MVLZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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