SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '92bf71145de065ded0bd7a79208abdce9561f1f1ef85c24dcfbfb3523f878db3' 
  AND token = 'fhM/eXvh2Ny8T8E+687uCZQFlyE+Wk+tDwSa6PDQAPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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