SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fa50db7499b518c4be12cfcefe4280f14aa1844b25cd8a6ff0d4a18687831a3d' 
  AND token = 'MgBBJgp7Zol1CORzRofm+5oAJ4t5jTRendGDs3oQoPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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