SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0be12f4889956cd04fa230705a1365ee8993c6c2a55e11ddd385325c616367f2' 
  AND token = '9oaXar+4dli/8av7Uz3BQxZJvH+26JopRKSvCwBYsZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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