SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecff4bc52b997764512a0deac8f5d633515f3c3680aa89407a02460b9198fa41' 
  AND token = '3r8owP6VrCyv+dJuDR1qFNyQtKYzxAypnkn9WTv4bms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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