SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd1ff64eb0859bf6527a579ffc56350b5806d09d8b6c5d5f1e98927692e53b34c' 
  AND token = 'JotLgR1eTzU8TrDTdODAmGm7yt/5rfyMpNOmYyO9iYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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