SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '87748910cb5263f910e3d462ce55b49c3735b527f64a925e9ee910d1ebc19cdf' 
  AND token = 'Iaj78z6PmJRAzvD6zmKIHgpL43h7hO8d0pQgmYCwA0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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