SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edce66fd29db9c91917264c4ab51e04f3d6258b1ac322858b4784fcaffe8f29c' 
  AND token = 'f7frDdNGVo1WLiGnizYYuv041cuhW1ljPMPP9sJ+zI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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