SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '012b4a875b21fad0d495c1bf72462b9dc4a549741630a1ca3baa3556e4187678' 
  AND token = 'a6vJNobmHAcqOjHi56QsthrAOHoj+vGFz5KXzIz1H/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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