SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e70cc708263a5f191ce1f1374cfff24d7c15258975ffaa0b29b243f420defdf' 
  AND token = '9MVWe0v4sB3fkIaMphFknR+XTvXtLRHSX76SafshJDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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