SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74c5680c3ee22c43f92841fb3d7260923bffc32881472955220d443d74145f9d' 
  AND token = 'QnvQDUlV0FBjGQg7YJLAPkCuzf4AMAXfP8F0SkKqwwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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