SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3a281642d4fd3e24f474ca150653579c6ec96d84997f3a8dff2cd5d2fc918bb' 
  AND token = 'a//diLTq7DrhXXyekL3aJ1Y3YxtChsDiHDOeIP5FE8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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