SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c2bc8c4502c67dd074ca963197c4988117ec50daf765f3853a87fe9a9ca58eca' 
  AND token = '/QvD4stL7/KvzksHqZpVOjXkVYs3jvHvkTImPmCvMxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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