SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d36cbfbcb5b41b00fe2b0b7324ef4a0518a06c8d92b3e82f169dd013ddc43fb' 
  AND token = 'Q27DfJu+3sAgPEp8VEi8K1xTBTL6hmbBG2c19uSM8jQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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