SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c0e899e602b7ec0d613dc6b65dbbdcd9994ba4e5661ce0cd30456ac20d8d75f8' 
  AND token = 'LuvaJERxx57lQ1rZsgPfuOwwrWktPZEXjMBr/FNxYWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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