SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6f11dff4c39cca4d93a2a68ae10c821e91e04feafc6cd5422f6f26fccc3f9e1' 
  AND token = 'qt/B7xg3a0O0jXMKVaxImhCvUqUE3uS5BSWfElcOiQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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