SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6698da5c25db46b64aa0b299e9171eb0cc270bb3754acbc1cde640579b9e8539' 
  AND token = 'QOqzDFfowzu8siGx9rYFAU1vLkCxHqBi2yWBvBdxJRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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