SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fcc6c4fa7faa0ecf273225bd0878146fdbe3fd228fd7f6ded3c21f431ca8753d' 
  AND token = 'WfEL6NGoUPUj2EF0cfdtP+BeZxI+5LGGGyRqrNbHzfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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