SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fad3c5a6f5bc757c3324390143408bfee724bdd31fc97f8ddf0c5658da2a1bb4' 
  AND token = 'r0Q4tOldvvRIXxxkCbdkdXJuTlGYxonrLXwvcZQn3+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}