SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '722e9acaed5a8b8e92f6b209abe04a5e56975110e712a4799ef3a973e81b16ff' 
  AND token = 'D1ieDeSInXVtB1MSOyOLM9wzvksRuzM8Thkv06wbcY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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