SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6411ca3add06947a1256e84413630f2c309e78c11d273b45fad9ea1bf543d75b' 
  AND token = 'C5dWRXxIK3I1HQ9MbKzd8diNURj+GjOcjg6PD90ZFtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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