SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4543217d44127d419ba085b44dd06fbb48fc963e341f59fdf6110278ceef9efa' 
  AND token = 'fAHSncMLcZM2vcdKmlXR5zCpvknPvwSp1+PvX83aCVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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