SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a8703e21953863b07f32376954db6e9eefbc3783e95d971664dca69cd849ffb0' 
  AND token = 'VaCWi3W8GQm3beQcKHyp1o/9J0Nm+zfa4xur7GfecAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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