SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '06c9d4ee6762ee0cd5b49df98b4b508c71d0148d983ed072a2f5f3c277486a4d' 
  AND token = '/u/Kh+SCxokKQGq8hs5f/zgN9i8r2Z4hm14ZT86rV/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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