SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c1f9e2eef6e115d6d1ce0b5d1cf009d2d8b8372211b343c2686bdd5f1d8ccf5' 
  AND token = 'x8GzuqkVwN/HcNIpLTgefa8ApiBU/Lj87Sy0HXDZ0WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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