SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '603826d3d8cc707068bcef21092f64080a6714d3f27288021760aabafa338e62' 
  AND token = 'JSUH1DxMEaJO2Y5WBehkl2G5Z3bdNGibEi0cAqOWIMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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