SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4dd5075f8a50690fad1bcec2068268c65b4e3da78ed8b7a774e9fc2a7df235ef' 
  AND token = '1PZvzE63zLhqdwjfP9tTSmQiWboCrgGkjNx08JgXyp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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