SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5232d5f7a883774fda0960e0b2d95caa9f4366bebfc2a8620063175019e44954' 
  AND token = 'mbS+Eh58RdEYBCq/FKPjMwjON1DJ4nyDhguvGBUlnM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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