SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd28aa476fae615fd9fd311807d441ac2b08ac0f81c4b2c0246a5a3e116c54de' 
  AND token = 'b8ETDj/ZaCPF70Q3UGGLx6oivMO6EdnbzJk4gXZMJv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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