SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a50550a8a914710f18e958dbf887a39cc7ca0953ca6966d19c96c6d3d3c8385' 
  AND token = 'FjvS/Yo6QuKjG+DAz/fGC4GV/gneP6iFJcWtYpB9Ao4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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