SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e75227d872d5fe19358b3b59f0b483be6abd3a791969255a1ae6d1a394b07685' 
  AND token = 'mTvnsFDpL5osHKL8rkZojQBszxqkx99Hg/Z0QHc7OKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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