SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9853886a4fe0e0793d66a003f885771b7a31a556e9855a0682200d3bcdd7b615' 
  AND token = 'qCRVJoGASh50ddbmjnohaz4ZHxRIMb5w1HSTgg+oDjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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