SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fae8b91996d283f55ad13d46243f1659c2c1f330f8775d15de4d9623b96b9ec' 
  AND token = 'Cbu9/zLwyADqbcHVDoYjA6CEyYLC/Vzv6h7doB/dTMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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