SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acb9425cec7b1af7f25330b8ac6f7e544b7176a2c42a5bc08e132ef5b9bc19d1' 
  AND token = 'R+qsf9vqdft/KMdDvq7PVzKC9uV2YjthsZ0t04z8yxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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