SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b747bf26d882812ad62c5e459a71139bba6dd58f690272a649124d23c9f0cff4' 
  AND token = '3qAliVjRY282tD8QS6ghM/szqfa/aPtlxB+KeSSkeFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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