SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6975cfcabf0c0ece923f15382e3413f57a735fadeb9e51acb684dffb30c32e8' 
  AND token = 'LZQY2/Cyg3wXejDu68r6webzZtZ2ifET0f8fwqwP9wU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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