SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97be914dbaeb18e95689ebe93e7b817db2f9b35054a6c87327007f22d699f501' 
  AND token = 'ERTK5W8OaGlABQ00uvgxY50PfirN+snV0zqwKj27rsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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