SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f15fb0f4dd2f4f32736cda53266b2b0f121c2fbe99870cb0918fe98a6eb04727' 
  AND token = 'sqmGxwU+z+mBlC4Mm+MKwlQQMraudmDEZdytBN8fHuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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